Welcome to the Forum.
Please check the rules if you haven't checked them out yet! ^_^
TechBroManSir already gave you good hints, I'm going mainly to link links.
I think, regarding to your question, the WALKTHROUGH - Free Player may help you a lot, even if you aren't a free player, it has a lot of informations how to obtain a 4* & 5* & 6*.
Also check The Beginners [ GUIDE ] to Trading.
In generel, you can acces Fantasica Encyclopedia any time and look for guides that may help you or you go to the Forum Game-Discussion and you can ask your questions here.
Also, if you've any questions, don't hesitate to ask them!